Novel Immunomodulatory properties of Uva-ursi folium extract
Arctostaphylos uva-ursi folium (bearberry leaf) is traditionally used for the treatment of symptoms of mild recurrent lower urinary tract infections such as burning sensation during urination and/or frequent urination. In addition to the antibacterial activity, it has also been suggested that preparations of Uva-ursi folium possess anti-inflammatory beneficial properties.
In the present study, we investigated the effects of an ethanolic Uva-ursi extract and the corresponding herbal medicinal product Cystinol® akut, on cytokine release in human primary peripheral monocytes. Uva-ursi extract and Cystinol® had no effect on the basal release of IL-1β, IL-6, PGE2 and TNF-α, while basal IL-8 release was dose-dependently stimulated. Uva-ursi extract inhibited LPS-stimulated IL-1β, IL-6, PGE2 and TNF-α release, whereas the LPS-stimulated IL-8 release was increased. Similarly, Cystinol® inhibited the LPS-induced IL-1β, IL-6 and TNF-α release and dose-dependently enhanced the LPS-stimulated IL-8 release.
For now and first time, these results showed that Uva-ursi extract and Cystinol® inhibited the release of pro-inflammatory cytokines in a physiologically reasonable dose range. Together with the induction of IL-8, a chemoattractant and an important normal urothelial growth factor , these results suggest that Cystinol® possesses anti-inflammatory/immunomodulatory effects, which may additionally contribute to the benefit of Cystinol® in treating urinary bladder infects. The possible clinical importance of these findings should be interpreted together with results of in vivo studies.
 Tseng-Rogenski S, Liebert M. Am J Physiol Renal Physiol 2009; 297(3): F816 – 21